Hi I have a Debian "Slink" 486DX4-100, with 1Gb IDE and 2GB SCSI II hard disks (hda and sda) partitioned and mounted on /, /usr, /home, /var, and /usr/local.
I also have a 420Mb SCSI II hard disk (sdb) which has no fixed mount point, but which I am using to store stuff I don't access frequently, eg, moving downloaded *.deb files from /var/cache/apt/archives. I leave my box running Debian all the time, day+night, and the 1Gb IDE and 2Gb SCSI disks are fairly modern, and very quiet, but this 420Mb disk consumes a fair amount of power, and sounds like a large aircraft taking off. I have configured this drive to respond to the "start/stop unit" SCSI command, and configured the Host Adapter (PCI AHA 2940 fast SCSI II) to send the "start unit" command to this drive during system boot. What I need to know now, is (how) can I send the start/stop unit command when Linux is running, so I can keep the thing spun down when is not mounted (which is most of the time), and only send the command to spin it up again when I need to mount it. I know that you can do this in FreeBSD, (which I run on another PC), the command is "camcontrol stop [channel:device-id:LUN]" or "camcontrol start [channel:device-id:LUN]". I presume there is also a way I can do this in Linux? What packages (if any) will I need to add using Dselect? Hope someone can help (and I can take out these earplugs :-) Simon Hales